Internal-combustion engine.



1,102,400, Patented July 7, 1914.

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FREDERICK FISHER, 0F MABLBORO, MICHIGAN.

INTERNAL-COMBUSTION ENGINE.

Spectacatton of Letters Patent.

Patented July 7, 1914.

Application 111er! Hay 7, 1806. Serial No. 315,481.

To all whom, it may concern Bo it known that I, Fannnaicic Flsunn, citizen of the United States, residin at Marlboro, in the county of Lake and State of Michigan, have invented a certain new and useful Improvement in Internal-Com bustion Engines, (Case 1,) of which the following is a full, clear, concise, and exact description, reference being had to the accoinpaiiying drawings, forming a part of this specification.

vIn the ideal Otto cycle the gas (not necessarily fuel) which is the agent for the transformation of energy, is heated at constant volume, the )ressure being corres )ondinrrly increased. n the Carnot cycle and the it cal cycle of the Diesel motor the heating takes )lace at constant temperature, that is, durin" the Supply of heat to the gas, cx )ansion takes place of such a character that tlie teinperature. of the vas is maintained constant. As distinguishe from a great variety of mechanisms intended to carry outl these cycles of the prior art, my invention provides for the use of a cycle which more or less closely approaches the ideal of heating at constant pressure. Practical limitations and considerations are such that neither the ideal Otto cycle, nor the ideal Carnot cycle, nor the ideal cycle. of the Diesel motor are attained in practice. Neither is it essential that the ideal condition of constant pressure during heating should be fully attained in order to make use of my invention. But a recognition of the ideiil cycle which is utilized in the practice of my invention Will enable. those skilled in the art to make wide modifications and changes without sacriticing the fundamental advantages which my invention is adapted to secure.

A\ly iiiveiitiou contemplates the use 0f reci )roeating mechanism in conjunction with w iieh power is intermittently developed` as, for example, in a combustion chamber associated with a cylinder and reciprocating piston. lleating of the gaseous agent of transformation takcs lace periodically` due to the combustion oi, a suitable fuel iii air or other combustion supporting medium. Consequently there will be corresponding changes in the pressure and temperature nnless means is provided for increasing the volume during the periods of combustion whereby the pressure may be maintained constant, or as nearly constant as practical limitations and requirements may dictate.

t To this end my invention contemplates the association of a reservoir with the combustion chamber. In order to carry outl the idciil condition of absolutely constant pressure darin heating, this reservoir is constantly unt er a stress equivalent to the pressure at which heating is to begin. The reservoiris adapted to receive and store energy whenever the pressure in the combustion chamber tends to rise above the )redetermined maximum limit. this energy eingr returned to the combustion chamber whenever the pressure therein falls below thc pressure at which limiting occurs and which corresponds with the stress in the reservoir.

I shall describe certain nualitications of my invention, and after referring broadly to sonic of the advantages to be secured, shall designate in the ap )ended claims the limitations and scope of tlie invention which I seek to protect.

1n the accompanying drawiii s Figure 1 is a plan view of an engine eni odying my invention; Fig. .2 is a cross-sectional view thereof, taken on line 22 of Fig. 1; Fig. 3 is an end elevation, parts being shown in cross-section; Fig. 4 is a diagrammatic view showing the application of my invention to .so-called two-cycle. engines, and Fig. 5 is a lon itudinal crosssectional view of a li hier anc smaller tvpc of engine than that siiown in the other igures.

lu Figs. 1, Q and 3 I have illustrated the )referred forni of my invention, in which like characters of reference apply to like parts. At 11 there is an engine cylinder iu which the plunger piston 12 reciprocates. 'llie motion of the piston is transmitted hv means of the connecting rod 13, the crank pin 14 and the crank 15 to the main shaft 16, upon which the flywheel 1T is mounted, these parts constituting the wcll-kiiowii transmission gear of reciprocating engines. 'l`he rear end of the workin f cylinder coininunicates directly with the llower end of a combustion chamber 18. As indicated in the drawings, the combustion chamber is tillcd to a greiitcr or less extent with water or other suitable. liquid which comes directly in contact with the rear end of the piston l. At 10 there is an energy storing reservoir. there being a )tissage wiiy 20 leading from the interior o the reservoir to the combustion chamber. this passage way being controlled by the float ball valve 21, which constitutcs a check valve, the operation and function of which willmore fully appear. let and the exhaust'valves being closed dur- Suitable valve mechanism serves to admit periodically a charge of fueland a combustion supporting medium to the upper endof the combustion chamber. Thus', 'for' 1n-Y stance, in this preferred embodiment of my invention, I have shown an inlet valve 22 arranged to admit, at proper intervals, a. combustible mixture, such, for instance, as air and any of the well-known hydro-carbons used in internal combustion engines. A spring 28 tends to maintain -the'valve 22 in p ace upon the seat formed in the lower part of the valve casing 24. The exhaust port 25 is equipped with'an exhaust valve 26, and a cam 27 and actuating lever 28 and a connect-A ing rod 29 serve to -actuate the exhaust valve by way 'of the toggle joint 30, the lower member of the toggle joint-being pivoted at 31 to the top of the valve'casing 24, and at 32 to thezstem 33 of the exhaust valve 26l The operation of this embodiment of my -invention may be described as follows: As-

suming the engine to have been put in motion in any suitable manner, we may start with a consideratlon of the forward m0vement of the piston 12 within its cylinder 11.

As the piston sweeps through the cylinder a corresponding volum'e of water will be drawn fromthe lower -part of the combus* tion chamber to follow up the piston. This withdrawal of the water from the lower part of the combustion chamber will cause the level 0f the water in the combustion chamber to fall, tending to create a vacuum in the upper part of the combustion chamber. The, suction causes the admission of a suitable charge of the combustible mixture through the inlet valve 22. The upper part of the reservoir 19 is filled with a compressed gas; such, for instance, as air, which has been forced into the reservoir through the opening 35, this opening being fitted with the check valve 36 and a plug 37 to prevent leakage. The air in the' reservoir is compressed to a high degree; such, for example, as three or four hundred pounds per square inch, and it is the degree of this Initial and constant. stressin the storage reservoir which determines the substantially constant pressure at which the heating of the working gas occurs. During the admission stroke of the piston the pressure in the reservoir serves simply to maintain the ball valve 21 upon its seat, thus clfectivcly closing the passage way between the reservoir and the combustion chamber and preventing any Y change in the potential energy stored in the reservoir. 'lfhe momentum of the flywheel causes a return or rearward stroke of the pistou Within its cylinder. The expulsion of the water from the rear end of the cylinder into the combustion chamber causes a compression of the combustible mixture in the top of the combustion chamber, both the instood by those skilled in the art', it is possible to Secure an approximation of true -adiabatic compression 'sufficient for the purposes of ignition. If the compression of the working gas is relied upon to increase the temperature sufficiently for the purpose self-ignition, the initial stress or potential in the storage reservoir shouldlbe so adjusted that the closure of the cheek valve 21 will be maintained until after the ignition of the combustible. Y If combustion is caused by the substantially adiabatic compression of the working gas, the combustionwill be practically instantaneous in all parts of the mixture as distinguished from combustion started from a given point b` an electric spark or otherwise and which is thereafter propagated throughout the mixture. The combustion of the fuel innncdiatcly increases the energy of the working gas, tending to cause an incl-casein pressure or volume. The pressure will rise slightly to a degree equivalent to the potential maintained in the storage reservoir, when the preponderance of pressure in the combustion chamber will raise the check valve 21 from its seat, causing a How of water from the combustion chanh her into the lower part of the compression resem oir whereby an equalization of pressure in the reservoir and combustion chamber is maintained and whereby the heating of the working gas takes place at a pressure approximating a constant value to a degree dependent upon the sizeand precise construction of the storage reservoir. lu order that there may be eoniparalivcly litt-le resistance tending to prevent the equalization of'thc pressure in the combustion chan'iber, it is desirable to make the opening between the combustion chamber and the storage reservoir of very large dimensions. The heat of combustion will result principally in an increase in volume of the \\'orlringgas. The compression reservoir acts as a spring or weight acting against gravity, to absorb the power suddenly developed by the explosion of the combustible mixture. The low of water into the lower part of the compression rest-.rvoir floats the valve 21 clear ef its seat 20, and the infiux of water .serves to float the valve and maintain an operati\e communication or association of the pressure reservoir with the combustion chamber whenever the pressure in the combustion chamber exceeds the normal pressure iu the reservoir. Although' the ignition of the combustible may occur shortly before the dead center is reached, there is no .greatly increased pressure upon the piston and the moment-um of the flywheel is sullicient t0 carry the engine easily over the dead center.

After the engine has passed over the dead center, the piston commences its travel toward the front end of the cylinder. During this stroke, the working gas experiences an adiabatic expansion, the increase in volume of the gas bein" accompanied by a diminish: ing pressure. Ihe expansion of the air in the storage reservoir, acting like a spring under stress, returns to the combustion chamber an amount of energy approximately e tial to that stored in the reservoir during tie rapid heating of the working gas. When tie potential energy in the reservoir has diminished to its normal value suflicient water will have been expelled from the lower part of the compression reservoir to permit the valve 9.1 to seat itself, thereby closingI the passage way between the combustion chamber and the storage reservoir, whereby the condition of the stress in the reservoir is maintained and whereupon the iower delivered to the moving piston will lic derived wholly from the continued expansion of the working gas in the combustion chamber and not in part from the energy stored in the reservoir, as during the first part of the stroke. The expansion of the working gas in this embodiment of my invention acts upon the movin v piston through thc agency of the water w tici tills the lower part of the combustion chamber. When the piston has reached the forward end of its stroke the cam 27 which is operated by a suitable shaft connected by gearing 41 with the main shaft, actuates the valve gearing connected with the exhaust valve 2G, whereby the valve 26 is depressed to permit the expulsion of the gases of combustion during the succeeding rearward movement of the piston, this movement being caused by the momentum of the ilywheel. This completes one c cle of operations. and the succeeding oye e commences, as before` with thc admission of the working gas and fuel succeeded by its compression, ignition, hating, expansion and exhaust. 'l`hc flvwheet is so related to the speed of operation that its momentum will maintain a substantially uniform ratc of rotation.

)it ll l have shown a water inlet associated with the check valve Atil which permits the influx of water umler a slighty pressure from a suitable source of supply, through the supply pipe 44. Whenever the valve is depressed by the plunger -l connected with the eccentric Atti upon the cam shalt t0 the eccentric causes a small quantity of water to he admitted to the combustion chamber 1S. this admission of water taking place during the as iirating stroke or the exhaust stroke, or hotli, and serving to replace any water that may have been evaporated by the hot gases or the heat retained in the walls of the combustion chamber and the slight excess of water which passes out through the opening at the to of the combustion chamber serves to flusli the valve and valve seat to revent its fouling.

he mode of operation which l have thus far described is independent of the precise nature of the combustible mixture admitted to the combustion chamber. An engine of this type can be designed to utilize. any of the fuels now used in internal combustion engines; such, for instance, as liquid or gaseous hydro-carbons, blast furnace gas, producer gas, or even solid fuel, umler suitable condttions of operation. My invention provides means whereby foul or impure combustible mixtures may be used to advantage, because the gases of combustion do not come into contact with any of thc movin parte except the inlet or exhaust valves eit ier before or after ignition. Furthermore., the scavenging of the combustion chamber is complete with every full cycle of operation, because the rising level of the water in the combustion chamber expels the last trace of the waste gas of combustion from the top of the combustion chamber. The water serves also to scour the valve and valve seats. The constant passage of water through the combustion chamber serves to remove any abrasive solids from the combastion chamber, thereby preventing the wear upon the cylinder and piston which is one of the reatest ditliculties heretofore encountered 1n attempts to utilize cheap fuels in internal combustion engines. On account of the very high compression of the combustible mixture before ignition, my invention provides a means particularly well adapted for the use of pon' mixtures. When, as in this embodiment of my invention, it is desired to operate the valve which controls the passage way between the reservoir and combustion chamber automatically b the variations of pressure in the combustion chamber it is, of course, impossible to secure heating at an absolutely constant pressure of the working gas, but the pressure is practically constant as compared with the pressure which would result from the explosion of a mixture compressed to the temperature of ignition if the gas were restricted to constant. volume, as in thc internal combustion engines employing the well-known (Vitto cycle. lturthermorc, the degree to which the pressure during heating approximates a constant value may be controlled by the design of the storage reservoir. lf the storage reservoir takes the torm of an air compression chamber` as in the preferred embodiment of my invention, an increase in the size of the compression chamber will decrease the rise in pressure in the combustion chamber upon the ignition of the conduistible mixture.

In my description of this invention I have in min the broadest meaning of the term lilo storage reservoir and contemplate the use of any elastic medium whose stress ma be varied duc' to an increase in the energy o the working gas in the combustion chamber, or the use of any mechanism or medium whose potential energy may be increased by the eX- pansion of the working gas. My invention contemplates the conservation of the energy charged into the storage reservoir during heating of the working gas and the subsequent transformation of this energy in delivering power to the flywheel of the engine.

The water within'the combustion chamber of this preferred form of my invention serves not only to transmit power to the piston .but also to maintain the combustion chamber. andthe valve mechanism ata safely low working temperature, the replacement of the water being sulliciently rapid to cause effective cooling.

While I do not limit the embodiments of my invention. t-o any particular means for igniting the combustible mixture, the selfignition of the combustible by the compres sion of the working gas is simple and eective, and the presence of the storage reservoir prevents any harmful effects, even in case of pre-ignition. It is now well settled that the elieiency of an internal combustion engine depends very largely upon the degree of compression to which the working gas is subjected before heating, and my invention provides a moans for securing a very high degree of compression without any harmful consequences. The high mean effective pressure in the cylinder gives an engine of large capacity.

An engine cf my invention permits of inexpensive construction as compared with engines in which the working gas comes directly into Contact with the working cylinder and piston because, in an engine of my invcnl ion, water is the medium which must be confined by the moving joints, and it is very much' easier and cheaperto pack a -joint to prevent' leakage. of water than it is to ack a joint to prevent leakage of gas` under i h pressure and temperature. The valve mec anism required to admit the working gas and fuel and,to convey the waste gases/ of combastion from the combustion chamber may be very simply constructed in an engine of my invention. The principaldifliculties which are encountered in the proper lubrication of internal combustion engines, partieularly those of high eiieiency, are done away with iri Aan engine of my invention on account of the low temperature at which the moving parts are operated. The capacity of internal combustion engines as heretofore constructed has been very much limited on account of the ditliculties encountered in properly cooling the working parts of an engine in which there is a large free space in which vthe combustible mixture is ignited.

My invention obviates this diiliculty on account of the inherently low temperature of operation and on account of the inherentcooling due-to the continuous passageof water through the interior of the combustion chamber.

v'In conjunction with this preferredform of my invention I have illustrated mechanism for pulverizing coal or other solid substance and utilizing it as a fuel for the engine. Theveoal is fed to'pulverizing apparatus from a suitable hopper 47. It passes through the openin 48V to the interior of the grinding ring 49, w ere it is ground by two or more balls50, 50, which are driven by a boss 51 keyed to the main shalt 16. The inlet pipe 52 leads from the pulverizer to the casing of the inlet valve 22. The suction which causes the depression of the inlet valve produces a draft of air which enters through the opening 53 surrounding the main shaft and passes through the interior of the grinding ring 49 and thence through the inlet pipe 52 to the casing of the inlet valve 22. The air in passing through thil pulverizing mechanism picks up a cloud of pulverized coal and carries it to the inlet valve where it is admitted at proper intervals to the combustion chamber 18. I have indicated, furthermore, a governor for controlling the speed of the engine by throttling the admission of the combustible mixture to the combustion chamber. This governor in simplified diagram, comprises a collar 54 mounted upon th`e main shaft and to which the governor weights 55, 55, are pivoted. The outward movemant of the governor weights, due to 'centrifugal force, tends to move the isleeve 56against the compression of a governor spring 57. A flange 58 forming a part of the sleeve 56 serves to close the opening 53 to a greater or less extent., depending upon thc position of the governor weights, which in turn are' controlled by the speed of rotation of the`engine. It will be readily understood by those skilled in the art that other devices of suitable nature may be adapted to my improved engine for the supply of combustible mixtures of other kinds. The ressure of the air confined in the compression reservoir may be adjusted to correspond withY the nature of the fuel and other conditions of operation.

I have indicated at 58 a valve which is used for cleaning out the interior of the engine.

In Fig. 4 I havediagrammatically illustrated a modification of my invention, which I prefer to' call a two-cycle engine. Its principles of@ operation do not Adiffer broadly from those already described in connectin with the four-cycle type of engine. The lce'nter of the main shaft inthe two-.cycle ltype of Fig. 4 is indicated at 60. A crank extends from the main shaft to the crank pin,

vthe center of which is indicated at 61. The connecting rod is indicated by the dotted line 62, extending from the crank pin 6l to the Wrist-pin 62, this Wrist-pin being carried in the plunger piston 63. also indicated in dotted lines. The cylinder of the engine is shown ut (34, sind as in the fourctfcie type of machine.` this cylinder is open at its rear end and communicates directif with the combustion chamber 65. A Hunting hell votre GS controls the opening through a passage way 67 from the compression reservoir titi to the combustion chamber G5. In order that the exhaust channel 69 may lead Vfrom the bottom of the combustion cham ber to n point 7.0 nenrlhe top of the comhustionchninber the center of this combustion chamber G5 is offset with respect to the cylinderv G4. At 7l I have indicated n bull valve controlling the opening -from the exhust channel 69 to the exhaust pipe 72. The inlet check vulve 73 controls communication from the inlet pipe 74 to the interior of the combustion chamber. At Z5 I have indicated un auxiliary compressor cylinder hav` ing n piston 76 actuated bv the connecting rod 77 which in turn is driven by the crank pin GI.

In operation this embodiment of my invention may he described as follows: Ne muy assume that the crunk-pin 61 is already in rotation in t ic direction of the nrrow 78 about the center oi rotation 50. This being the case,-the p'ston 76 of the conipreseor cylinder will commence its Stroke .troni the bottoni of the mflinder7 sucking in "o charge of air through the check valve 79 und the oir pipe 80. Upon the reverse Stroke oi the piston TQS this nir will he compressed to moderate degree, for example, to three yor four atmospheres. Aft-er this compres- Sion has continued to sonic degree. the nuxiliary scouring valve 81 is opened by a cnin .82 vniounted upon" the cmn shaft 83, which .in turn is geared at 84 to the moin shaftv of the'enginc. The opening of this scorn-ing,

valve permits n small amount of air to poss from the lower end of the compressor cyl inder through the inlet pipe 84,and the main inlet check valve 73 to the interior of combustion chamber 65. This combustion chamber. ns in the case of the. fourcvcle engine alrcndv described. contains n volume of water sufiicicnt for the purposes of operation, tov be hereinafter described.

.At the time when the scouring valve el is opened, the exhaust valve 7l will also he in an open condition, duc to proper actuation bv means of the cam 85. lThe air blowing in through the inlet check valve 73 Will scour-the interior of the combustion ychanoher of all residue which mar be left from u previous explosion. The com 85 permits the exhaust vulve Tl to seat itself'.l thus preventing the continued escape of gases er water from the interior of the combustion cheniber. The com 86 then actuntes the main inlet 'vulve 8T. which permits the balance of the air which hns been colnpressedin the auxiliary cmnpressfn cylinder to iioff through the inlet pipe 74 to 'the interior c* the combustion chamber G5. l have indu cated in this drawingl a means for utilizing powdered coni as n fuel. This consists essentinllr in n hopper 88 in which the powdered coni is placed and from which it is periodicallyv introduced into the inlet pipe in definitely measured quantities. This measured, introduction of the powdered fuel is accomplished by ineens ofc sliding plunger 90 actuated by n. connecting rod, indicated h v the dotted line 91. this connectingy rod lending to un eccentric 92 whose eccentricity is controlled by the inertiagovernor 93, the eccentric being pivoted nt 94. yThe reciprocntion of the plunger 90 causes n sin-:ill quantity of powdered coal to be forced through the supply pipe 95 und deposited Within the inlet pipe 84, as indicated at 9S. The compressed nir missing;r rapidly through the inlet valve 87 picks up this charge of finely powdered coul und Curries lt into the top oi' the combustion chanihcr. at the seine time thoroutrhlyH distributing it through the charge of nir which is admitted. et the same time. 'The Vcomloustilcle miX- ture having thus been introduced into the upper port of the coinlimstion chamber the continued movement ot the piston 63 causes the level of '.he Waiter in the combustion chamber lo rise and produce :i compression of the mixture in the top of the chamber. The consequent rise in temperato e eventually causes ignition und explosion of the mixture. As in the case of the four-cycle type of engine. the operative connection which is then established between the storage reser- Voir nud the combustion chamber inerente. the enormous rise in pressure which. would otherwise tolte place due to this high de- `nrce of compression before ignition.A lUpon the ignition of the mixture the tendency to increase the pressure in thc combustion chamber causes the Hunting vulve 68 to be raised 'from its scat. thus permittingV un influx ot inter from the combustion chamber to the storno/c reservoir. the stress or comv P l pression of the nir in the compression reservoir beingu increased by un muount depending"r upon the relutice proportions of the combustion chamber and the other parts of the engine. This storage of energy in the compression reservoir serves to equalize the pressure in the reservoir and combustion chmnher whereupon the outward of the pistou commences under pressure substantially equal to that of the air in the com pression reservoir and continuing; until the pressure has been so far reduced ne to cause the expulsion of some of the wtr from the movement 'indetinitely.

compression reservoir which permits the floating valve 68 to seat itself, the seating,T of this valve when the pressure in the storage reservoir has reached its normal value breaks the operative association of the compression vreservoir with the combustion 'chamber, whereupon it is the continued .the lower part of the combustion chamber,

drives the exhaust gases of combustion from the top Lof the chamber through the exhaust channel G9 and the exhaust valve 71 to the exhaust pipe 72. During this part of the cycle, during: which the pressure in .the combustion chamber is very low, water flows into same through check `valve 98 from supply pipe 99, supplying the water needed to replace that evaporated and to scour the valves. The excess water travels from the combustion chamber into the top of the exhaust channel and is expelled through the exhaust pipe. .As previously explained, thel scour ing valve 81 will again be opened shortly before the exhaust valve 71 is closed so as to insure the expulsion of any residue of exhaust gases of combustion before the influx of the succeeding charge of air and fuel. Shortly before the main piston (i3 reaches the end of its backward stroke, the auxiliary coniprcssorpiston 7G will have accumulated another charge of compressed air which will he blown into the combustion chamber with its quota of fuel, whereupon the above described cycle of operation will be repeated The slide valve 100 is connected with the end of the measuring plun ger 90 and controls the openingr of the pipe 80 to the atn'iosphere. During the instroke lof the piston G3, the exhaust valve 71 is held in its open position b v the operation of the cam 85 on the shaft, 83 until the piston 76 has nearly or quite completed its instroke. During this interval the valves 81 and S7 are closed and air is compressed in the pipe 80 to a certain degree. say three or four atmospheres. During this interval the ,frases of combustion are partially expelled from the combustion chamber 65 by the water beingr forced upward in said chamber by the inwardh7 movingr piston 63 and when this piston 63 has reached substantiallv the position shown in Fig. 4`the valve 81 is opened for a brief interval to permit a part of the compressed air in the pipe 80 to flow through the check valve 73 intothe combustion chamber 65 and out through the pipe 69 and the exhaust valve 71, carrying with it, the remaining products of combustion and a part of the water from the upper portion of the combustion chamber to complete the scavenging of the same. Then, with the piston 76 still in substantially its innermost. position, the shaft 83 `has rotated the valve cams 82, S5 and 86 sufficiently to permit the exhaust valve 71 to rest upon its seat and the valve spring to close the scouringr valve S1 and to op'en the main intake valve 87. The compressed air remaining in the pipe 80 now rushes rapidly through the pipe 74 carrying with it the powdered fuel 96 through the check valve 73 into the upper portion of the combustion chamber since the pressure in the said chamber was practically atmospheric at the instant of opening the valve 87. Equalization between the pressure in the pipe 80 and the combustion chamber 65 at once takes place and a decrease in pressure in the combustion chamber is prevented by the closed exhaust valve 71 and the check valve 73. The fuel mixture at this timeis under a low pressure. say two atmospheres in the combustion chamber. which pressure is not sulficient to .spontaneously ignite the charge Vlhe piston G3 now completes its inward stroke and compresses the charge of fuel and air mixture to a very high degree owing' to the conical shape of the upper portion pf the combustion chamber, fuelis ignited b v the high temperature developed. The pressure thereby produced iS communicated to the piston 63 and the pressure relief chamber and the cycle of operation described above is repeated indenitely. 'lhis modification of my invention. like that illustrated in Figs. ,1. l and 3, may be adapted by those skilled in the ait to burn other fuel than powdered coal. The advantages heretofore pointed out in connection with the` four-cycle tvpe of engine are present in the modification illustrated in Fig. 4, the latter form having such other advantages as are secured in .engines having a power stroke for every 'revolution of the fly-wheel.

In Fig. 5 I have illustrated still another modification of my invention, the essential principles of operation being the same as those inherent! to the embodiments heretofore described, one of the principal differences being that the storage reservoir is incorporated into the main piston of the engine. The engine shown of the four-cyc1e type. I have shown a main cylinder V110 in which the piston 111 reciprocates. The center of the main shaft is at 112 and the motion of the piston is transmitted to this shaft through the connecting rod l113 and the crank 114. The piston is made hollow as shown and thus provides the storage reservoir. The ring 115 clamps to the top of thepiston a diaf phragm 116 of rubber or other flexible material of like nature. A metal button 117 coversl the top' of the diaphragm and is preand the 1n this Fig. 5 is o' to the action if said l wsten. inlet valve meeh- :inism for admitting a combustible mixture lo aid combustion chamber duringy an outstrole ot2 the piston. such comlmfftion chambei so conformed that the inertia of the liy wheel serves upon the succeeding instroke to et npress the combustible mixture to the point ut' ignition`r an exhaust Valve contr lling the exhaust from said combustion chamber. valve mechanism for automatically epenirg; and maintaining communication for the dow or' liquid between the two ehambers whenffrer the pressure in the combustion chamber exceed3 a predetermined limit, the parts involved in compressing the eombustible mixture bung prolmrtioned to pro4 duce Sul'stantially adiabatic Compression of the ctmabusti'eie mixture to the point et ignition.

l. In an internal combustion engine, the eomhination of a working cylinder, a reciprocating piston therein, a ily wheel and a connecting rod nieehanisn'i for connecting the liy wheel and piston. a combustion chamber communieatiner with said cylinder, an excess pressure relief chamber containing gas in its upper portieri and Vin communit'al'ion with the comlunion chamber. a liquid parfiullj.' filling both chamber,`4 and subject to the action of' said piston, inlet \f'al\fen1eeh anisin 'for admitting a combustible mixture tf: said combustion chamber duringy an outn strelie of the piston. the inertia of the ily wheel :sai-rvingr upon the succeeding iirstroke to compress the cinnluistible mixture to the point of ii'rnirion. an csha'ist valve controllint`l the ex Aaust from said combustion ehamberg valve mechanism `for autoi'natically openingr and maintainingr eofnmunication for theiiuw of liquid between the two cham liars whenever the pressure in the combustion chamber exceeds a predetermined limit, the parts involied in compressing the oomihle mixture being proportioned to pro-- l, e sul ntially adi Vie compression ot' the combusibl-fe mixture to the point of igniA tien, and means. 'for admitting fre-1h liquid to the chambers during' each cycle of the en I.eine7 the exc-:rs liqaid being ejected duringr the erinfiusting .stroke of the piston.

l. in an internal lcombustion engine, the i. on of a working V eyliiidcr, a retingj pistfn (herein, a fly wheel and `,ting red mechanism associating the r, heel ,i d. piston. a, combustion ehamliier 'inzun'i ating with said cylinder. an excess pre `ire rf chamber, a liduid partially t" n :f het i chairmen; and subject to the ae-l 'Jau .of'suid pistou, there being an openinf: in l'liflttfmi et' the relief chamber through which the liquid may lion' between the two faber#4 a valu- "n the openingy between the uint ion an'. reiie irhamit-crssaili ya l'vc beinaintaffw in an open condition while the relief chamber remain:

l i l l l j l 1 above a predetermined normal pressure, in` let valve mechanism for admitting a con1- bustible mixture to the combustion chamber, an exhaust valve controlling the exhaust from the combustion chamber, the parts subjected to the pressure of compression being so formed and related as to produce a compression pressure sufficient to ignite the combustible mixture without material loss of heat.

5. ln a device of the class described, the combination et a combustion chamber, means for admitting fuel and a combustion supportingr medium into said combustion chamber, a cylinder having a reciprocating piston therein. a liquid in said cmnbustion chamber for transmitting power between said conibustion chamber and said piston and from said piston to said combustion chamber for compressing the mixture in the combustion chamber, an excess pressure reliel chamber, there beingr an opening from the lower part of the relief chamber into the combustion chamber7 said opening being below the level of the liquid in said eombus tion chamber, a float Valve for closing the opening between the chambers, said Valve being fioated from its` seat upon an inllux ot liquid from the combustion chamber, the valve being lleated from its seat during the period of excess pressure in the combustion chamber, the pressure in said relief chamber heine' maintained at such a point that the return ,stroke of the piston may compress the combustible mixture in the cornbustion chamber to the point of ignition belore the float valve will open to establish communication between the two chambers.

ln an internal ecmbustion engine. a working eig'lindcr. a combustion chamber connected to such cylinder, a pressure relief chamber. there being a passageway between the relief and the combustion chambers, and a cheek valve located in said passageway and moxable to different posit ions according to the pressures in the relief and combustion chambers for establishingr free communication between said chambers in either direction atove a, predetermined pressure.

7. ln an internal combustion engine. a working' cylinder, a combustion chamber connected i ith such cylinder.y a pressure reliel' chamber integral with the combustion chamber and adapted to prevent excessive pressure therein` there being a passageway between said chambers, means controlling said passageway for preventing communication between such chambers below ak predetcrn'iincd pressure` and a gas-admission valve, for the relief chamber movable to an inoperative position by pressure in the reliefE chamber above a predetermined limit.

ln an internal combustion engine, a working: cylinder, a combustion chamber connected to such cvlinder, a pressure re- 

